Reservoir Characterization via Surface Displacement Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for characterizing subterranean reservoirs are inefficient and costly, often requiring drilling and flowing reservoir fluid to the surface, which poses environmental and safety hazards and lacks accuracy in determining reservoir characteristics without direct intervention.
Innovation Solution
A method that detects displacements at the earth's surface in response to stimuli such as pressure or temperature changes, allowing for the determination of reservoir characteristics like volume, permeability, and location without flowing fluid to the surface, using techniques like tiltmeters and satellite-based measurements, and applying tidal loading as a stimulus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If drill stem tests are used to characterize reservoirs, then reservoir fluid can be flowed to the surface for direct measurement, but environmental hazards and safety hazards increase
Solution Approach 1:
The patent replaces the mechanical system of drill stem testing with a geophysical method using surface wave propagation. Instead of physically bringing reservoir fluid to the surface through drilling equipment, the invention uses acoustic or elastic waves generated at the surface that penetrate into the reservoir and return information about reservoir properties through their interaction with subsurface structures. This substitution eliminates the need for drilling operations and fluid flow to surface, thereby removing environmental and safety hazards while maintaining measurement capability.
Solution Approach 2:
The patent introduces surface wave propagation as an intermediary between the surface measurement location and the reservoir target. Rather than direct contact with reservoir fluid through drilling, the surface waves act as a mediator that carries information about reservoir properties (such as velocity, attenuation, and impedance) from the subsurface to surface sensors. This intermediary approach allows indirect characterization of the reservoir without the harmful effects of direct intervention.
2Measurement precision
If drill stem testing is performed to evaluate reservoir characteristics, then direct measurement is possible, but the cost of transporting equipment and crews increases
Solution Approach 1:
The patent replaces complex drilling equipment and specialized crews with simple surface wave generation and detection systems. Instead of requiring drill stems, wellbores, and specialized testing equipment, the invention uses surface-based sources (such as vibrators or explosive charges) and geophones or other surface sensors. This substitution dramatically simplifies the equipment required and eliminates the need for specialized drilling crews, reducing operational costs while maintaining the ability to evaluate reservoir characteristics.
Solution Approach 2:
The patent creates a surface-level representation or copy of the subsurface reservoir properties through wave propagation measurements. By analyzing how surface waves interact with subsurface structures and return to surface sensors, the invention creates an indirect model or copy of reservoir characteristics (such as velocity profiles, impedance variations, and structural geometry) without needing to physically access or extract samples from the reservoir. This copying approach eliminates the need for complex in-situ measurement equipment.
3Loss of information
If drilling is performed to obtain reservoir information, then direct access to reservoir is achieved, but substantial drilling costs are incurred
Solution Approach 1:
The patent replaces the expensive mechanical drilling process with a non-intrusive geophysical survey method. Instead of physically drilling into the reservoir to obtain information, the invention uses surface wave propagation that naturally penetrates the subsurface and interacts with reservoir structures. The information is obtained through analyzing the returned wave signals, which contain encoded data about subsurface properties. This substitution eliminates all drilling costs while preserving the ability to acquire comprehensive reservoir information.
Solution Approach 2:
The patent enables the reservoir to provide its own information through the natural propagation and interaction of surface waves with subsurface structures. The reservoir's own physical properties (such as velocity, density, and structural geometry) naturally influence how surface waves travel through and reflect from it. By measuring these wave interactions at the surface, the reservoir essentially serves itself by providing the measurement information without requiring external intervention such as drilling or sampling.
4Measurement precision
If traditional methods are used to determine reservoir characteristics, then direct measurement is possible, but the ability to optimize drilling locations is reduced
Solution Approach 1:
The patent creates a universal surface wave measurement system that can characterize multiple reservoir properties (velocity, attenuation, impedance, structural geometry) and can be applied to evaluate multiple potential drilling locations across a large area. Unlike drill stem testing which is limited to a single well location, the surface wave method can survey extensive regions and provide comprehensive subsurface models that guide the selection of optimal drilling locations. This multi-functional capability allows the same measurement technique to serve both reservoir characterization and drilling site selection purposes.
Solution Approach 2:
The patent transitions from one-dimensional point measurements at individual well locations to two-dimensional or three-dimensional areal coverage through surface wave propagation. By generating waves that travel through and reflect from subsurface structures across a broad area, and by using arrays of surface sensors, the invention creates spatially distributed measurements that map subsurface properties over large regions. This dimensional expansion provides the spatial context necessary to identify and optimize drilling locations based on the overall reservoir structure and property distribution.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate characterization of reservoirs without drilling, reducing costs and environmental impact, and providing valuable information on reservoir properties and fluid mobility, while optimizing drilling locations and production rates.
Implementation Method 1
The stimulus may be applied to the reservoir by human intervention, for example, by applying the pressure change to the reservoir via a wellbore intersecting the reservoir
Implementation Method 2
The stimulus may instead, or in addition, be applied to the reservoir by periodic tidal loading. The tidal loading may be gravitational force exerted on the earth by a heavenly body
Implementation Method 3
The tidal loading may also be hydrostatic pressure applied to the surface of the earth due to ocean tides
Implementation Method 4
The reservoir characteristic determined in the method may be the volume, shape, location, permeability, porosity, or compressibility of the reservoir
Data Source
AI summary
Reservoir characterization based on observations of displacements at the earth's surface. One method of characterizing a reservoir includes the steps of: detecting a response of the reservoir to a stimulus, the stimulus causing a pressure change in the reservoir; and determining a characteristic of the reservoir from the response to the stimulus. The response may be the pressure change which varies periodically over time, or a set of displacements of a surface of the earth. In another example, a method includes the steps of: detecting a set of displacements of the earth's surface corresponding to a pressure change in the reservoir; and determining a characteristic of the reservoir from the surface displacements. In yet another example, a method includes the steps of: detecting a set of displacements of the earth's surface corresponding to a change in volume of the reservoir; and determining a characteristic of the reservoir from the surface displacements.